Pump



p 2, 1930. w A. s. PARKS 1,774,663

PUMP

Filed July 1929 3 Sheer.s-Shee'. 1

1 Sept. 2, 1930. s, PARKS 1,774,663

PUMP

Filed y 1929 3 Sheets-Sheet 2 A S. PARKS PUMP 3 Sheets-Sheet 5 Filed July 24, 1929 9 Am 5m l 6%@ Patented Sept. 2, 1939 I p v 1,774,663.

warren sTA'rss PATENT OFFICE ARTHUR- Ei. PARKS, OF SANDWICH, TLLINOIS,

PUMP

Application filed July as,

This invention relates to pumps, and more particularly to pumps of the rotary valve type.

One of the objects of the invention is the provision of a new and improved valve mechanism for a pump.

Another object of the invention is the provision of a new and improved multi-cylinder pump having a single valve for the cylinders and so constructed that it functions as an intake and a discharge or exhaust valve.

Another object of the invention the provision of a new and improved pump mechanism that is adapted to be employed either as a vacuum or asa compression pump.

A further object of the invention is the proision of a new and improved pump that is cheap to manufacture, easily assembled, composed of a minimum number of moving parts, and that is economical and efficient in opera-- tion.

Otherand further objects and advantages of the invention will appear from the follow ing description, taken in connection with the acgompanying drawings, in which Fig. 1 is a vertical section of-the device in the plane of the crank shaft thereof;

Fig. 2 is a vertical section on the line 22 of Fig. 1;

Fig. 3 is a section on the broken line 33 of Fig. 1;

Fig. 4 is a section on the broken line 44 of Fig. 1; 1

Fig. 5 isa section on the line 55 of Fig. 1;

Fig. 6 is a section on the line 6-6 of Fig. 5;

i Fig. 7 is a bottom plan View of the valve;

Fig. 8 is a section onthe line 88 of Fig. 7; and

Fig. 9 is a bottom plan view of a modified form of valve.

Nhile the pump may be employed as a compressonit will be described,'for conven ience of disclosure, as a vacuum pump'The pump is especially adapted for vacuum pump work in connection with milking machinery, in which efficiency and economy in cost of operationare of prime importance.

Referring now to the drawings, the refercnc'echaracter 9 designates the pump casing, the upper portion of which is in the form of 1929. Serial NO. 380,505.

a cylinder block 10, provided with a plurality of cylinders, as 11 and 12. The lower portion of the casing 10 is in the form of a crank case in which the crank shaft 13 is rotatably mounted. The crank case 14 is open at its lower portion to provide access thereto, and is provided with a closure 15 for retaining lubricating oil therein.

The crank case 14 is provided with alined openings 16 and 17, within which are secured the hubs 18, 19, of the bearing retaining members 21, 22. These members are provided with flanges 23, 24, which are adapted to be attached to the crank case, as by means of the bolts 20, for holding said members in posi lion. The anti friction bearings 25, 26, are mounted in counterbores in the hubs 18, 19, clearly shown in Fig. 1 of the drawings. The crank shaft 13 is journaled in the bearings 25, 26, in the vusual manner.

The bearing retaining member 21 is pro vided with an enlarged cavity or recess 27, within which is adapted to rotate an oil retaining member 28, secured to the crank shaft 13. A. passage 29 connects the recess 27 with the crank case for returning oil escaping from the member 28 in the usual manner. An oil retaineror ring 31, of well known con- Stl110131011,1112t7 be mounted in the outer end of the bearing holding member 21 forpre venting the escape of oil along the crank shaft 13. One end of the crank shaft 13 is provided with a pulley 32 for rotating the same. i

The cylinders 11 and 12 are provided with pistons 33. 34, which are adapted to be reciprocated by the crank shaft 13 by means of the connecting rods 35, 36, as is usual in such constructions. The cylinder block 10 is provided with a removable cylinder head 37,

which is adapted to be attached to the flange 38 on said head in any suitable manner, as by'means of bolts 39. The cylinder head is provided on its upper surface with a valve seat 40.

The cylinder head 37 is provided with a conduit'or port 41, extending therethrou h and in communication with the cylinder T1, and with a similar conduit or port 42, ex tending therethrough and in communication with the cylinder 12. The head is also provided with a passage or port 43 (see Fig. 2) which extends from the upper face of the head 37 to the outer edge thereof. A fitting 45, having an opening 46 therethrough (see Fig. 2), is adapted to be attached to the edge of the head 37 with the opening 46 in communication with the passage 43. A pipe 47, attached to the fitting 45, is adapted to be placed in connnunication with suitable ve iel from which the air is to be exhausted, it it is desired to use the pump a vacuum pump. Suitable valve means are provided for alternately bringing the conduits 41, 42, into communication with the passage 43.

in the form of construction selected to illustrate one embodiment of the invention, a rotary valve is employed for this purpose. The valve 48 is provided with a mental recess or c: vity 49, having the curved extension 51 concentric with the hub portion extending about the axial Opening 30 of the valve. When the valve 48 is in the position shown in Figs. 1. and 2, the conduit or port 42 of the cylinder 12 is in communication with the recess 49, as shown in Fig. l, and at the same time the recess 49 is in cont munication with the passage or port 43, as shown in Fig. 2. The valve 48 also provided with a permanently uncovered segmental opening 53, extending transversely through the same and concentric with the hub portion The segmental opening 53 is at the same distance from the axis of the valve as the upper ends of the conduits 41, 42, so that these conduits are placed alternately in communication with the opening 53 when the valve is rotated.

Suitable means are provided for rotating the 'alve. As shown, the valve is rotated by a shaft on the lower end of which is mounted a gear meshing with a gear 56 secured to the crank shaft 13. The shaft 54 is jonrnaled at its lower end in a portion 57 of l0. connecting the two cylinders. The collar 58 limits the dmvi-iward movementof said shaft. The upper end of the shaft is journaled in the head 37. and extends through an axial opening 30 in the valve 48. This valve is slidably mounted on said shaft. A cross-bar 59, provided with depending pins 61. is rigidly connected to the upper end of the shaft 54. The pins 61 are adapted to extend into recesses 62 in the valve 48 for causing said valve to rotate with the shaft 54. The valve 48 is held on its seat by light springs 63, mounted on the pins 61.

It cap 64, detachably connected to the head 3? by means of the bolts 65. extends over and protects the valve mechanism. This cap is provided with a screw-threaded opening 66. to which a pipe 6? may be connected if desired.

In the operation of the device the crank shaft 18 is ope ated in the usual manner by muses the pulley 32, which will cause the reciprocation of the pistons 33, 34. In the position of the parts as shown in Fig. 1, the piston 33 is nearing its upper limit of movement. At this instant the piston 34 is traveling downard, and if the device is being used as a vacuum pump air is entering from the vacuum chamber through the pipe 47, opening 46, passage or port 4?), the segmental cavity 49 of the valve 48, and the conduit or port 42. Atthe same time air is being forced out of the cylinder 11 through the conduit or port 41 and the opening or discharge port 53, into the atmos ihere or into the cap 64, from whence it passes to the atmosphere through the pipe 67.

The parts are so constructed that the pistons approach within a few thonsandths of an inch of the head. 37; consequently almost all the air drawn into the cylinder on the return stroke discharged on the outstroke of the piston. hen the discharge port is closed practically ll air drawn into the cylinder is discharged on the outstroke except what little amount remains in the passages 4L and 42, and since these passages are very short the device unusually efficient as a pump for commercial purposes.

It has been found that considerable energy may be saved when operating the device as a vacuum pump. by arranging the exhaust port 53 so that it remains closed until the piston is about 30 past dead center. Y hen operating the device as a vacuum pump, if the exhaust valve is opened at the beginning of the return stroke, especially after the device has been operating a short time, air will rush into the cylinder since the pressure therein is below that of the atmosphere. This air must be discharged, and the friction of the same passing through the port requires more or less energy. 011 the other hand. if the port is not opened until the piston has passed dead center a considerable distance. the atmospheric pressure on the lower side of the piston will assist in forcing the same outward, thereby greatly increasing the elhciency of the device. The initial outward movement of the piston will compress the air within the cylinder to a pressure more ne; rl v that of the atmosphere, so that the column of air rushing into the cylinder after the exhaust valve is opened will be greatly reduced.

By placing the passage or opening 46 or pipe 47 in communication with the atmos- "phere and by connecting the pipe 67 with a receiver, the device may be operated as an air compressor. If a more ellicient air compressor is desired, the valve 48 may be substituted for the valve 48. The valve 48 is of the same construction as the valve shown in Fig. 7, except that the port 53 will be extended 30 to make the same symmetrical relative to the recess 49*.

By changing these valves and reversing the direction of rotation of the driving pulley 32 the device may be used as an air compressor without disconnecting the pipe 47, hen thus operated, the vacuum chamber is used as a compression chamber or as a container for the compressed air.

I claim as my invention 1. In combination, a plurality of pump cylinders, a piston for each cylinder, a single combined intake and discharge valve for all of said cylinders, said valve comprising a disk having a permanently unobstructed passage therethrough, and means for operating said. valve in timed relation to the operation of said pistons.

2. In combination, a plurality of cylinders, a plurality of pistons in said cylinders, a cylinder head having a passage therethrough for each cylinder, a. valve having an intake and an unobstructed discharge conduit, and means for moving said valve for placing said passages alternately in communication with said intake and discharge conduits.

3. In a vacuum pump, a cylinder, a piston, a common intake and discharge port for said cylinder, a rotary valve for said port, said valve having an unobstructed discharge passage therethrough, means for rotating said valve in timed relation to the reciprocation of said piston to bring said passage into communication with said port after said piston has moved a substantial distance beyond dead center.

4:. In a combined vacuum and compression pump, a pump casing, a pair of cylinders spaced apart integral with said casing, a piston in each cylinder, a crankshaft journaled in the lower portion of said casing for operating said pistons, a cylinder head having a port extending therethrough for each piston and having a passage extending from one edge to the top surface thereof, a rotary valve for bringing said cylinders alternately into communication with said passage through said ports, and spring means for holding said valve on its seat.

5. In a combined air'compressor and vacuum pump, a cylinder head comprising a plate, a pair of .ipassages extending through said head, said passages diverging toward the cylinder-engaging face of the plate, said head being provided with an opening extending from one side of said plate laterally to an edge portion thereof.

6. In a combined air compressor and vacuum pump, a pair of cylinders, a pair of pistons in said cylinders, means for operating said pistons, a cylinder head extending across said cylinders, said head having a conduit extending therethrough for each cylinder, said head having a valve seat, and an opening extending from said seat to the atmosphere beyond said cylinders, a rotary valve having a recess and an opening therethrough,

on said seat, said opening bein unobstructed, means for rotating said valve to bring said recess and opening alternately into communication with said conduits, and opening, respectively, and a cap over said valve.

I. In a vacuum pump, a casing having an oil compartment in its lower portion, and a pair of cylinders in its upper portion, pistons for said cylinders, a crankshaft journaled in said oil compartment, means connected to said shaft and pistons for reciprocating the same in opposite directions, a drive gear on said shaft, a valve operating shaft extending upwardly from said oil compartment between said cylinders, a cylinder head having intake and exhaust passages, a rotary valve having a recess in one portion, and an unobstructed passage extending through the same at another portion, said recess and passage being adapted to be brought into communication with the intake and exhaust passages of said cylinders, a spring abutment on said valve operating shaft, a plurality of springs between said abutment and said valve for holding the same against said head, and a cap for enclosing said valve and abutment.

8. In a pump, a pair of cylinders, a piston for each cylinder, means for operating said pistons in opposite directions, a head for said cylinders, said head being provided with a discharge passage for each cylinder and having an intake passage extending from the upper surface of said head laterally to the edge thereof, a single rotary valve having a recess in its lower surface and an unobstructed passage extending transversely therethrough, a shaft extending upwardly beween said cylinders through alined openings in said head and valve. a cross member secured to said shaft and having pins thereon for engaging recesses in said valve, springs on said pins for engaging said valve, a cap having a discharge passage, secured to said head over said valve, and means for rotating said valve for bringing said recess and unob structed passage alternately in communication with said intake and discharge passages.

In testimony whereof I herewith aflix my signature.

ARTHUR S. PARKS. 

